Sound-receiving apparatus



March 4, 1924. m2555139 W. L. WALKER SOUND RECEVING APPARATUS Filed May 1l, @921 5 Sheets-Sheet l 1.9 w w19 7 ,la 27m March 4., 1924. 1,485,539

W. L. WALKER SOUND RECEIVING APPARATUS Filed May ll. 1921 3 Sheets-Sheet 2 44 if W March 4 1924.

, 1,485,539 W. L. WALKER SOUND RECEIVING APPARATUS Filed May ll. 1921 3 Sheets-Sheet 5 771; (KZL/o :f7-ley Patented Mar. 4, 1924.

UNITED STATES PATENT OFFICE.`

WILLIAM L. WALKEE, OE NEW YORK, N. Y., AssIGNoE To WALKER SIGNAL ANI)y EQUIPMENT CORPORATION, OE NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SOUND-RECEIVING APPARATUS.

Application led May 11, 1921.

T all wlwm t may concern.'

Be it known that I, WILLIAM L. WVALKER, citizen of the United States of America, and resident of New York, in the county Of New York and State of New York, have invented new and useful Improvements in Sound- Receiving Apparatus, of which the following is a specification.

This invention relates to signalling systems and more particularly to that type of system wherein is employed a sound receiving or listening devicel or ear submerged below the surface of a body of water through which the sound disturbances are propagated. In certain systems of this type 1t is usual, in view of the necessary thinness of the diaphragm employed, more or less to balance the pressureupon opposite sides thereof in order to avoid distortion of the diaphragm by the pressure of the water to which it is subjected and to enable the diaphragm to vibrate in equilibrium. When the diaphragm forms one wall of a closed box or housing such balancing-of pressure has been accomplished by providing a pipe of substantially uniform diameter leading from the interior of the box and having free 4 communication with the water in which the diaphragm is submerged. \Vith this ar- 30. rangement it is necessary to employ a pipe of very substantial vertical length in order to `provide a sat-isfactory column of compressed airintermediate the water column and the inner side of the diaphragm. This is setv forth in my previous application Serial No. 17 6.299 tiled June 22, 1917. The employment of such extended vertical pipes i is in many cases undesirable for practical considerations, especially when a pluralityy of such 'receiving devices are located at various parts of a ships hull, on account of the number of holes required to admit water and the cost and complication of the piping system required. Moreover, where such a pipe is Acarried to a point above the diaphragm housing thereis always present the possibility of the accidental flow of water into such housing with consequent damage to the delicate parts enclosed thereby. Furthermore, when such sound receiving device or ear-is mounted upon the hull of a vessel, the hydrostatic pressure to which it is subjected may vary very considerably and at a rapid rate due to the rolling of the ship.

If in such cases the pressure balancing. pipe serial' Nb. 463,612.

herent in devices such as have been employed for thisl purpose. To this end it is proposed to employ means permitting the vertical height of the water column to be materiall shortened and maintained at practicaly the height 0f the diaphragm,

thus rendering the apparatus more compact and at the same time avoiding any probability of accidental discharge of water into the diaphragm housing while at the same time substantially preventing the surging of the water column and damping the fluctuaf tions of pressure in the sound4 receiving device. Moreover, with a compensating device of relatively large volume such as herein referred to, .the height of the water column being maintained at practically the same height as the diaphragm, the pressure on both sides of the diaphragm would be approximately equal. As one mode of accomplishing this result the conduit 'leading from the interior 'ofthe listening device to the exterior of the ship may have interposed therein a casing'providing a relatively large chamber connected to short pipes of relatively large diameter, wherein a substantial volume of air is supplied for compression to balance the external hydrostatic pressure. With such an arrangement the fluctuations of water level in such chamber andrpipes being much less than in a smaller pipe of uniform diameter7 there is correspondingly less rapid variation in air pressure in the diaphragm housing. The pressure chamber may be located at such a point as respects the diaphragm housings as to make a 'compact and economical installation.

In devices of the above character, particularly when exposed to salt `water, the moist air contained within the pressure bal.- ancing pipe and above the column of water therein rapidly corrodes the delicate instruinentalities within the diaphragm housing and a further object of the present invenmeans whereby to avoid the difficulties intion is to minimize such undesirable action. As one mode of attaining the desired result,

that portion of such pipe adjacent to the hull it is of course necessary to provide pressure balancing.,r devices for each of such ears. This usually involves the provision of an equal number of water inlet openings through the hull with multiplied danger of leakage and necessitating careful inspection and frequent repair. The balancing device of the presentl invention however lends itself particularly well to employment with a plurality of such listening devices, as by connecting all of such devices to a commonpressure chamber, a single water inlet opening suiiices for all, while at the same time the entire system is made compact and little subject to damage.

The pressure chamber may if desired be formed in a casting having a head provided with the desired number of openings into which are fixed the ends of substantially cylindrical tubesto the opposite ends of which may be connected the pipes from the respective listening devices. The casting may also have supporting means mounted thereon whereby to protect the several tubes against accidental displacement or damage, the casing with its attached tubes thus forming a unitary device which may be manufactured in quantity for general use.

It is at times desirable, as for example when making repairs, or when by reason of leakage the usual volume of air in the pressure balancing apparatus has been de pleted, to introduce air into the diaphragm housings and pressure chamber, and a further object is to provide means whereb the desired result may readily be attaine To this end a header device having valve controlled connections to a compressed air supply may be provided, such headerhaving valve controlled communication with the pressure chamber and with the conduit leading from the latter to the diaphragm housings. If desired valves may be so arranged as to isolate from the air supplyeither` the housings or that portion of the pipe or tube adjacent the pressure chamber. Vixen the device is to be employed in a system having several ears or listening devices, a common header may be connected to all, and in such case the header may well be mounted upon the casing having the pressure receiving chamber.

A preferred embodiment of means for carrying into effect the above objects is disclosed in the accompanying drawings, in which Fig. 1 is a vertical cross section partly in elevation of a pressure balancing a paratus such as forms the subject matter o this invention;

Fig; 1l is a side view, partly in section of a sound receiving device such as may be employed in a signalling system of the type to which this invention relates;

Fig. 2 is a side elevation of the device illustrated in Fig. 1, taken at right angles to said figure; and

Fig. 3 is a plan lview of the apparatus shown in Fi 2, and Fig. 4 is a side elevation to smal er scale of a modified form of the device.

For purposes of illustration the device may' be considered as installed in a. ship whose outer plating or skin is indicated at 1. Within said outer plating is formed an opening 2 for the reception of a signal receiving device or ear such for exam le as that disclosed in the a plication o lVilliam L. Walker, Serial) No. 176,299 filed June 22, 1917, and which comprises in general a water tight housing or box 3 having a portion thereof seated within the opening 2 and having its outer wall formed by a diaphragm 4 arranged to lie substantially flush with the outer surface of the ships hull. From the interior of the box orv housing 3 leads a ipe 5 which is connected to the pressure ba ancing apparatus whereby to maintain the pressure within the diaphragm at a point substantially equal to the hydrostatic pressure of the water l upon the outer face of the diaphragm.

In accordance with the present invention the pressure balancing apparatus comprises a. casing indicated generally at 6 and which may be formed as a casting if desired. This casing comprises a lowerv and substantially cylindrical portion 7 whose upper end is closed by the wall 8 and the lower end of which may be closed by a removable plate indicated at 9. This plate is secured to the end of the casing 6 by means of bolts 10 and a gasket 11 is placed beneath said plate to form a tight joint between the same and the casing. At a central point the plate 9 has an outwardly projecting boss provided with an internally screw threaded bore 13 for the reception of a pipe nipple 14. To the nipple 14 is secured a valve casing 15 from which extends a pipe 16 communicating with the water outside the ships hull and at a point below the level of the listening device or ear. Through such pipe, in the normal operation of the device, water is freely admitted to the chamber 7a within the casing 7. If desired, grids or perforated covers 17, 17 a may be secured upon the inside of the plate 9, and the wall 8 respectively, as by means of screws 18, 18Et whereby to prevent the introduction of foreign matter into the chamber 7 a and further to prevent the too rapid movement of water into and from the chamber 7.

In the wall 8 is provided a Series of openings such as 19, 19, spaced apart in circular series and at substantially equal distances from one another. These openings may be screw threaded for the reception of the threaded extremities of cylindrical tubular members such as 20, 20. While herein shown as having screw threaded engagement-with the openings 19, 19, these tubes may be fixed therein in any other and desirable manner, as for example by headingr over the tubes upon the inside of the casing. The series of tubes 29, 20, extend upwardly from the wall 8 of the casing and substantially parallel one to the other. From opposite points in the casing supporting members 21, 22 project upwardly and substantially parallel to the tubes 20, 20a. Secured to the upper ends of the supports 21, 22 is a bridge member 23 secured to said 'supports as by means of bolts 24, 24. This bridge member is in the form of a plate having its central portion of a Width' sufficient to include the series of tubes 20, 20, such plate being providedwith openings such as 25 for the passage of such tubes.

' The bridge member as thus constructed, to-

gether with the supports 21. 22, serves to maintain the upper ends of the series yof tubes 20, 20, in proper operative relationship and to protect the same from blows or other injury. If desired, as in Fig. 4, the peripheral wall of the casing may be continued up above the wall 8 to form a cylindrical support for the plate 23.

Substantially at its central portion, the member 8 is provided with an opening 26 within' which is fixed the lower end of a tube 27 substantially like the tubes 20, 20, and extending upwardly through an opening 28 lat the center of the bridge member.

At its upper end each of the tubes 20, 20, etc., is preferably provided with an outstanding fiange 29 to'which is secured -by bolts a flange 30 from which extends a pipe nipple 31, the flanges 29,30 thus constituting al union. To the nipple 31 is secured the lower end of a valve casing 32 by means of which communication with the upper end of the tube may be controlled. The pipe 5- leading from the interior of the sound receiving device 3 is connected as by means of a fianged union 33 with a valve casing 34, such valve casing being directly connected if desired, with a T connection 35, the lower end of such T being connected to the valve casing 32.

To the central tube 27 is connected a valve lwith one of the passages 40 and with the While the foregoing description as to the connections between the header, the sound receiving device and the vertical tubes has been made with reference to one of the tubes.

only, it is to be understood that similar connections are employed for the entire series of such tubes. From the upper portion of the chamber 39 of the header 38 leads a passage 43 which communicates by mean's of a valve 44a with a pressure supply pipe 44 for air under pressure. The header also may be provided with a passage 45 having internal screw threads for the connection of a gage device 46a whereby the air pressure within the chamber 38 may be determined.

Within one or moreof the tubes 20` 20, and preferably in all thereof and if desired in the tube 27, may be arranged freely mpvable pistons 46, such pistons comprising heads 47 and guide flanges 48. Such pistons may be formed of any suitable material which will not be affected by exposure to salt water or moist air and as one such material hard rubbe-r is contemplated as being particularly adapted.

The pistons 46 may be arranged with their heads downward or upward as desired and preferably stop devices, such as 49 (if the bafiie plates 17*l are not employed) may be arranged at the lower ends of the several tubes for preventing projection of the pistons therefrom.

In the operation of the device described, it being assumed that each of the tubes as .20, 20, isconnected by the proper connections to a listening device or ear disposed lat a suitable point in the vessels hull, the

several valves 41 will be closed and t-he valve 15 will be open. The valve 36 may also be closed in the normal operation of the device, while all of the valves 32 and 34 will be open. As thus adjusted. water from outside the ship flows freely through the pipe 16 and into the lower portion of the chamber 7a, thus building up pressure within said chamber and forcing the pistons 46, if such pistons are used` upwardly in their tubes.l

This action continues until pressure within the housing 3 has been 'brought to a point substantially equaly to the hydrostatic pressure upon the Aoutside of the diaphragm. As the chamber 7Il is of very substantial siderable volume of air is trapped in the apparatus and that such air must be compressed into the relatively smaller volumel presented by the several tubes before water can rise into the lower ends of the tubes 20,

20a, etc. It is thus possible by the employment of this apparatus to avoid the necessity of using vertical pressure tubes of excessive height while the entiie apparatus is rendered compact and such as may be installed at a rela-tively low 'point in the ship`s hull. It may also be noted that changes in the pressure in the ears 3 due to rolling of the ship are not transmitted instantaneously to the pipe 16 (due to the relatively large size of the chamber 7a. the p-ipes 20 and 20, and the baiiie plates 17. lf). Thus not only are pressure variations in the diaphragm housing damped` but the affects ofthe surging of a long column of water in the pressure pipe are very materially reduced. If during the operation of the device it 'be found that air has escaped by leakage or otherwise from the chamber 7a or from the tubes 20. 20, the pressure in such chamber may be built up by opening the valves 36 or 41 and admitting compressed air from the pipe 44, the pressure thus built up being indicated by the dial of the indicator 46.

It is also evident that by the opening or closing of proper valves, the desired pressure may be maintained by compressed air instead ofwater. If through accident, as for example., the breaking of a diaphragm or of one of the pipes 5, the air is permitted to escape from o'ne of the tubes 20, the parts may be restored to normal position by shutting the valve 34 and opening the valve 41, whereupon compressed air from the header may ybe admitted to the upper end of the tube from which the air has been lost, thus forcing the piston 46 downwardly therein and rendering such tube operative when the desired repairs have been made. After such repairs have been made, by opening the valve 34, pressure may be built up directly in the diaphragm housing by the admission of compressed air from the header.

It is thus clear that a very flexible control of the elements of the device has been provided and that the apparatus as thus disclosed is adaptable for use lin many situations and without substantial change, it being contemplated that the device comprising the casing 6 with its tubes 20, 20, the header .38 and connecting parts may be manufactured as a unit ready for installation in connection with any desired signalling system in which one or more listening devices are employed having diaphragm chambers wherein the pressure must be balanced.

While Athe device herein disclosed is regarded as a preferred embodiment of the invent-ion, it is to be understood that various changes and rearrangements of parts might be made as well as substitution therein of well known commercial elements one for another without in any manner departing from the spirit of the present invention.

Having thus described the invention in a preferred embodiment of the same, what I claim and desire to secure by Letters Patent of the United States is:

1. In combination with a submarine ear for attachment to a ships hull below the water line, said ear comprising a closed chamber, a passage leading from said chamber and having its opposite end open to the entrance of water at a point below the ships water line, and means associated with said passage whereby to damp the violent surging of water therein' under rolling of the ship.

2. In a device of the class described a diaphragm subjected to hydrostatic pressure upon one side, and means constructed and arranged to provide a balancing pressure upon the opposite side of said diaphragm, said means comprising a water column and an associated pressure chamber of relative large surface area as respects the diameter of the column.

3. A pressure compensating device for use in a signalling system in which a diaphragm housing is employed, comprising a tube of relatively small diameter having one extremity in communication with said housing, a casing having a closed chamber of relatively large diameter into which the other end of said tube opens, and connections whereby water under pressure may be admitted to said chamber.

4. In combination with a submarine car comprising a closed housing for attachment to a ships hull at a point below the water line', a pipe opening into said housing, a casing providing an air chamber and with the upper part of which the said pipe communicates, a water admission pipe leading from the lower part of said chamber to the exterior of the ship at a point below the level of said ear, and means for admitting air under pressure to said chamber.

5. A submarine signalling apparatus comprising a housing having an opening in one side, a sound responsive diaphragm mounted over the opening` means for rendering the housing water-tight to permit it to bc submerged in a body of water, and means for controlling the pressure within said housing, said means comprising a duct opening into said body of water and having intermediate its ends a chamber of substantially greater cross sectional area than adjacent portions of said duct. v l

6. A submarine signallingv apparatus comprising a housing having an opening in one lll side, a sound responsive diaphragm mounted over the opening, means for rendering the housing water-tight so that it may be submer ed in a body of water, a passage communicating with the housing and extending to a point below the same, said passage at its lower end being open whereby water may rise therein and increase the pressure within the housing, and means providing an air chamber interposed between the ends of said passage and of a volume relatively large as compared with that of the remainder of said passage.

7 In a signalling system, a submarine ear comprising a water tight housing arranged for submersion below the level of a body of water, a pipe leading from the interior of said housing and having a normally vertical portion, a casing providing a chamber into which the lower extremity of said pipe opens, and a second pipe opening at one end into the lower portion of said casing and having its opposite end open for the entrance of water.

8. A device of the class described comprising a casing providing al chamber, a water admission opening at the lower portion of said chamber, a pipe having its lower end secured in an opening in the 'upper wall of said casing, and positioning means carried by said casing and having engagement with said pipe at a point substantially removed from its lower end.

9. A device for use in signalling systems comprising acasing providing a substantially cylindrical chamber, a water admission opening in the lower end of said chamber, an opening in the upper wall of said casing, a normally vertical pipe having'its lower end fixed in said latter opening, a pair of opposed supports extending upa wardly from said casing, and a bridge member having an opening for the passage of said pipe and secured at its opposite ends to said su ports.

10. A evice for use in submarine signalling systems comprising a casing having a chamber therein, a removable cover platev for closing the lower end of said chamber, said late having a water inlet o ening theret rough, and being provided wit pipe attaching means, supporting means extending upwardl from the upper end of the casing, a bri ge member secured at its ends .to the respective supports and having a guide opening therein, and a pipe assing through said latter opening and aving1 threaded engagement at its lower end wit an o ening 1n the upper end wall of said 11.` A device for use in submarine .signalling systems comprising a closed casing having a water inlet opening at its lower portion, a plurality of substantiallyI parallel tubes opening at their lower ends into the upper part of said chamber, and a positioning device spaced from said casing and supported thereby, said positioning device bemg provided with guide openings for the respective tubes.

12. Av submarine Signalling system comprising a, plurality of listening devices, valve` controlled pipes connecting each of said devices with a common pressure balancing chamber, a common header also having valve controlled communication with each of said pipes, a pipe connecting said header with said balancing chamber, means to admit water under pressure' to said' chamber, and means to admit air under pressure to said header.

13. A submarine signalling system comprising a listenincdevice, a pressure balancing chamber, andl a compressed air supply, and means permitting selective communication between said air supply and said chamber or listening device respectively, and for cutting off communication with said air supply and providing a free passage between said chamber and listening device.

14. A signalling system comprising a plurality of submarine ears, a casing providing an air chamber, a plurality of substantially parallel tubes opening into said chamber and communicating with the respective ears, and means for admitting water to the lower part of said chamber.

15. A submarine signalling system having a plurality of listening devices, and a common pressure balancing device therefor, said device comprising a casing having an air chamber therein, means for admitting water. under pressureto the lower part of said4 chamber, a plurality of substantially parallel tubes extending from the upper wall of said casing and communica-ting with the res e'ctive listening devices, and a valve controlled conduit for admitting air under pressure to the upper portion of said chamber.

16. A `signalling system having a plurality of listening devices and a pressure 'balancing apparatus therefor comprising a substantially cylindrical casing providing a pressure chamber, means for admitting water under pressure to the lower portion of said chamber, a plurality of substantially parallel tubes corresponding in number to said listening devices, said tubes being s aced substantially equally in circular ser1es and fxedly secured in openings in the upper wall of said chamber, means connecting each of said tubes with its respective listening device, a centrally arranged tube securedl in an opening in the upper wall of the chamber, a header device connected to the upper end of said latter tube, means for connecting said header with each of said Afirst-named tubes, and means for admitting air under pressure to said header.

lll

17. A pressure compensating device for use in signalling systems comprising a closed receptacle providing a chamber of substantial volumetric capacity, a tube leading from the upper portion thereof, means for admitting fluid under pressure to said chamber, and a freely movable piston slidable in said tube.

18. A signalling system comprising a diaphragm housing, a pressure balancing device comprising a passage leading to said housing and into which passage Water may be admitted, and means in said passage' for preventing the passage of moisture into said housing.

19. A signalling system comprising a diaphragm housing, a pressure balancing device comprising a chamber into which water is admitted, a passage between said chamber and housing, and movable means lto obstruct lthe movement of moisture along said passage.

20. A signalling system comprising an in strument housing, means providing a passage between the interior of said housing and a body of water, said means comprising a substantially cylindrical conduit, and a piston freely movable in said conduit whereby to reven-t the introduction of moisture into sald housing.

21. An apparatus of the class described comprising an instrument housing, a ressurebalancing device comprising a c amber, means for admitting water under pressure to said chamber, a conduit connecting said chamber with the interior of said housf ing, said conduit comprising a substantially cylindrical ortion, and a plston freely movable in said) cylindrical posi-tion under the effects of unbalanced pressures upon its opposite sides.-

22. A device of the class described comprising a diaphragm subjected to hydrostatic pressure upon one side, and means constructed and arranged to provide a balancing pressure upon the opposite side of the dia hragm, said means comprising a water co umn, and baille means for obstructing the rapid rise and fall of said column.

Signed by me at Boston, Massachusetts, this seventeenth day of December, 1920.

WILLIAM L. WALKER. 

